This invention relates to an interface system, methodology and protocol used by data gathering computers to gather data, and by analysis and display computers to display and/or analyze the data gathered by the data gathering computers, and more particularly to an interlace system, methodology and protocol for use by a data gathering computer which utilizes a unified control program to control the gathering and storing of data and a display and analysis computer which utilizes the unified control program and stored data to reconstruct the data values, units, and other information.
This logging equipment is used to measure sensors and store the results of these measurements for later analysis. A logger could, for example, measure three sensors (e.g., temperature, pressure and humidity) once a second and store the results in memory. Usually when a sensor is measured by a computer, the result is an integer value which can be converted to engineering units by a mathematical equation. The logger could store these results unambiguously by first converting the data to engineering units and then storing them, for example, in a form below:
Time: Jul. 19, 1990 10:56:38 PA1 Tire Pressure: 15.43 psi PA1 Engine Temperature: 25.34.degree. C. PA1 Intedor RH: 73% PA1 Time: Jul. 19, 1990, 10:56:39 PA1 Tire Pressure: 15.43 psi PA1 Engine Temperature: 25.34.degree. C. PA1 Interior RH: 73%
Here the first line defines the time that the measurement was taken, and the subsequent lines of each block show the parameter measured, its value, and the units of measurement. Even this might not be enough, for example, if two pressures were measured, a location of these two measurements would be needed as well (manifold pressure and tire pressure, for example).
This is an extremely inefficient storage method for storing data, since a large fraction of the information is repeated each time it is stored. Most data logging equipment eliminate the redundant information by storing the measurement result in its most primitive form, leaving the conversion to engineering units for a separate computer that is used to analyze the stored data. This optimizes the storage efficiency, but makes it impossible for the data analysis computer to convert the data to engineering units without additional information telling it the sequence of measurements and the equation needed to convert the stored data to engineering units.
One solution to this problem is to write a separate data analysis program for each data gathering program, an approach that has two disadvantages. First, for every modification of the data gathering program, a similar modification must be made to the data analysis program, and second, each newly written analysis program must be tested to confirm its proper operation. These two problems can vastly increase the time needed and cost involved in data analysis.
It is therefore an object of the present invention to provide an interface system, methodology and protocol for use by a display and analysis computer and a data gathering computer wherein only one program is required for both controlling the measurements and storage, and for guiding the analysis of the stored data, instead of requiring two programs (one for gathering and one for analysis), greatly simplifying the process of data gathering and analysis. This single program can be called the "unified program."